As is well known, in a rotary machine such as a gas turbine, a steam turbine, a compressor, a water wheel, a freezing machine, a pump, or the like, a device disclosed in the following Patent Document 1 is provided as a shaft sealing mechanism configured to seal a rotation shaft.
FIG. 14 is a schematic perspective view showing a configuration of a shaft sealing mechanism 100 in the related art.
The shaft sealing mechanism 100 includes a shaft sealing device 102 accommodated in a housing 101 that encloses a rotation shaft R at a stator side of rotary machine.
The shaft sealing device 102 includes a stacked body 103, a high pressure side side sealing plate 104, and a low pressure side side sealing plate 105. The stacked body 103 has a plurality of thin plate pieces 103a stacked along a periphery of the rotation shaft R in a circumferential direction. The high pressure side side sealing plate 104 covers a portion of the stacked body 103 at a high pressure side of the fluid. The low pressure side side sealing plate 105 covers a portion of the stacked body 103 at a low pressure side of the fluid. In the stacked body 103, base end sides of the plurality of thin plate pieces 103a are mutually connected, and tips are free ends. The base end sides of the thin plate pieces 103a are accommodated in the housing 101. Each of the thin plate pieces 103a extends from the housing 101 toward the rotation shaft R to be inclined from a radial direction of the rotation shaft to a tangential direction.
In the shaft sealing mechanism 100 having such a configuration, while the tips of the thin plate pieces 103a contact the rotation shaft R with predetermined pre-compression when the rotation shaft R is stopped, a lifting force is applied to the thin plate pieces 103a by a dynamic pressure effect when the rotation shaft R is rotated. As the lifting force is used, a micro gap is formed by the thin plate piece 103a and the rotation shaft R to seal a working fluid, and wear between the rotation shaft R and each of the thin plate pieces 103a is prevented.